Forms of energy (upper elem/middle) (teach)

ENERGY Upper elementary or middle school level

By Moira Whitehouse PhD

This show has many animations from the “animationlibrary.com” and from PowerPoint. These won’t be viewable until the show is downloaded. When just viewing some pages will seem to have information stacked on top of other information.

We cannot directly see energy. We only observe the effect it has on matter. If matter moves or changes, we will learn that energy was used to make it to happen.

In science the word Energy means the ability to move or change matter.

Everything we do involves energy. Getting up, going to school, figuring out our math problems and doing chores at home.

When we walk or run, drive a car, cook on a stove, heat our food in a microwave oven, or switch on a light, we are using energy.Matter of fact, everything that happens in the universe, from the eruption of volcanoes, to the sprouting of seed takes energy.Sometimes it happens slowly.

Sometimes very fast.

A world without energy is difficult to imagine but it would be a dark place without sound or light or any movement.

There are several different forms of energy. Each one however either causes or can cause matter to move or change.

Mechanical

Thermal (heat) Electrical

Sound

Electromagnetic (light)

Nuclear

Chemical

We will talk about each kind of energy, starting with

Mechanical

Every moving object has mechanical energy, whether it is a hammer driving a nail, a leaf falling from a tree, or a rocket flying in space. Any object that is moving can cause another object to move. Mechanical energy pulls, pushes, twists, turns and throws.

A moving hammer has mechanical energy. When it hits the nail, it causes the nail to move.

What causes the ball to move when it hits the bat? What about when you kick a ball. What causes the ball to move?

When you hit a ball with a bat, the ball flies.

Both the bat and the kicking feet have mechanical energy; they caused the balls to move.

Sound

NEXT

Sound energy involves vibrating objects.

When you strike a tuning fork, it vibrates back and forth and makes a sound.

When a boom box produces sound, the speakers vibrate.

When something vibrates it causes the air around it to vibrate as well. These vibrations may travel to our ear. Our brain interprets the vibrations of a violin string as music.

It works like this: the vibrations travel through the air to our ear, are sensed by our ear drum which moves little bones, causing fluid in a canal to move tiny sensor hairs. Our brain senses the motion of these hairs as sound.

Thermal

Thermal energy exists because objects have heat. Heat is caused by the motion of the tiny particles that make up everything. Just as TV pictures are made up of tiny pixels, everything is made up of atoms and molecules. These tiny particles are always in motion but we can’t see them or the motion because they are so small. But we know the faster they move, the hotter they get.

When an object absorbs thermal energy, the molecules and atoms that make up that object move faster and its temperature rises.

Yes, they got warmer. Why do you think that might happen?

Rub your hands together. What did you notice?

When you rub your hands together, you create friction which causes heat between your hands. This heat that you feel is there because the friction caused the molecules that make up your skin to move faster. As a result, you increased the amount of thermal energy in your hands and they feel warmer.

We use thermal energy to cook our food, to heat our homes, to generate electricity and many other things.

Aren’t you glad that someone discovered that thermal energy changes matter. Look what changes occur when we bake a cake.

Adding and subtracting thermal energy can also change matter from one form to another by making molecules move faster or slower.

ICE WATER VAPORICE WATER VAPOR

Electrical

All matter consists of atoms,

and every atom contains one

or more of these electrons,

which are always moving.

When electrons are forced

along a path in a conducting

substance, the result is a

current of energy called

electricity.

Electricity is the energy of electrons moving in an electrical conductor, like wire. Electrons, remember, are one of the three particles of which every atom is made.

This is a diagram of an electric current of electrons moving in a closed circuit. What do you notice happens when the circuit is open? .

Many things that are very useful to us run on electrical energy.

Chemical

Energy stored in the bonds of atoms and molecules is called chemical energy. When some substances react with one another, chemical energy is released.Probably the most familiar example of chemical energy is the dry cell battery that you use so often.

metal cap (+)

carbon rod (positive electrode)

zinc case (negative electrode)

manganese (IV) oxide

moist paste of ammonium chloride

metal bottom (-)

When these different substances react with each other, electric energy is released providing power for your flashlight, radio, or whatever.

Photosynthesis is perhaps a more important example of chemical energy. Plants absorb light energy from the sun which causes a reaction between the carbon dioxide and water in plant leaves creating a sugar called glucose. Plants can change glucose into carbohydrates and fats, storing chemical energy for later use.

This “stored for later use” covers a lot of territory. It could be:

•Used by the plant itself for growth and survival.

This “stored for later use” covers a lot of territory. It could also be:

•Plant parts could be eaten by animals, starting a food chain for feeding earth’s creatures.

Plant absorbs light energy and transforms it into

chemical energy

The grass is eaten by the _________is eaten by the _____is eaten by the ______is eaten by the ______.

Stored _________ energy in the plants is transferred from the __________to the_____, to the _____to the ________enabling each to live and reproduce.

Energy transfer in food chains

Where did the plant get the energy to make food with stored chemical energy?

Just as animals, we humans must eat and digest substances (like fruit, vegetables, and even meat of animals that had eaten plants). In the process, the chemical bonds between the atoms and molecules in the food are broken down, releasing chemical energy. This is the energy we use to walk, run, jump, grow and live.

This “stored for later use” covers a lot of territory. Finally, it could mean:

•plant parts buried underground for a long time, decaying and turning into the energy resources of oil, gas or coal, our three fossil fuels.

Natural gas and crude oil (petroleum) were formed from the remains of plants and animals that died millions and millions of years ago.

Crude oil and natural gas have a lot of stored chemical energy from those plants and animals that died millions of years ago.

Both oil and natural gas are pumped out of their reservoirs found under layers of rock.

Some of this gas is then piped to our houses where that stored chemical energy is changed to heat to cook our food and heat our homes and water.

After natural gas is removed, it is stored in tanks above ground.

Crude oil, on the other hand, is sent to a refinery where it is separated into its various parts. One of these parts, gasoline, when burned in our cars releases stored chemical energy.

Coal, our third fossil fuel, is a black shiny rock also found underground.

We dig it up and burn it to generate electricity.

Coal also was formed from the remains of plants that died millions and millions of years ago.

Natural gas, crude oil and coal have vast amounts of chemical energy stored in the bonds that hold their atoms together. When they are burned, this chemical energy is released.

light

Light (one type of electromagnetic energy) is a form of energy that allows us to see. Electromagnetic radiation which comes from the sun has parts other than light such asx-rays and radio waves, but it is light that the human eye sees. This picture

shows the same place in day and at night. What do you see in this scene during the day that you can’t at night? Why?

Think of several ways that you use light energy. Note them on your paper.

Did any of these pop up in your head?

The brightest light you can probably think of is the sun. Because of solar panels, sunlight can now be used to make electricity, which we learned earlier, can be used to do many things.

In these pictures light from the sun is being changed into electrical energy. Can you label each picture with the kind of energy the electricity produced?

________________ energy ________________

energy

________________ energy

In areas of the world where there is lots of sunshine, solar panels can be used to provide the electricity needs of peoples homes and many other things.

Nuclear

Nuclear energy is the last form of energy that we will talk about.As we learned earlier, all matter is made of atoms. The nucleus or center part of an atom is made up of smaller particles called protons and neutrons.

nucleus

Nuclear energy is produced in two different ways. In one, large nuclei are split and a large amount of energy is released. In the other method, small nuclei are combined and even more energy is released.

Here small nuclei are joining to form a larger nucleus.

Here a large nucleus is breaking into smaller nuclei.

This reaction releases even more nuclear energy.

Releasing a great amount of nuclear energy.

Nuclear energy is released on the Sun...

...and in nuclear power plants where electricity is generated.

About 300 years ago, scientists figured out an amazing fact about energy: it cannot be created nor destroyed, it can only be changed from one kind to another. Here we see chemical energy being changed to electrical, then light and heat energy.

So much for nuclear energy, now an important fact that is true of all energy.

For the rest of this presentation, you will be shown examples of energy being changed form one form to another. You will be asked to identify the type of energy in each part of the examples.

In a boom box, electrical energy is changed to______________ energy.

Electricity can be changed into many other forms of energy.

electricity coming into motor

With an electrical motor, electric energy is changed to ________________ energy.

We use a blender to mix different fruits and vegetables to make juice or smoothies. To mix these drinks, it has an electrical motor that spins very fast and makes a whirring noise.

In this example, ___________ energy changes to ___________ and _________ energy.

The sound is of no use to us, but the blended makes it anyways.

Here the person made a switch that turns on an oven. The red lightning bolt stands for electricity coming from outside the home and is connected to the oven. What happens when the person closes the switch so that electricity can flow to the element in the oven?

In this example, electrical energy changes to __________ and _________ energy.

A child blows a whistle. When he blows into the whistle he moves air through it and the whistle makes a noise.

In this example, ______________energy changes to ___________energy.

In this example, ______________energy from the Sun changes to ___________energy which then changes back to ________ energy.

Here a solar panel is being used to power a school zone light.

With an electrical fan, electric energy is changed to ________________ energy.

In this example the toast turns brown. This change happens when ______________energy changes to ___________.

A spring pops the toast up when it’s done (_________energy)

If you look inside the toaster, you would see red glowing coils. This change is the results of __________ energy changing to __________energy.

In this example, ______________energy changes to __________ energy.

A cat is strumming a guitar.

In this example, ______________energy changes to __________ and __________energy.

Here we see wood burning. Do you remember what kind of stored energy is in wood?

In this example, ______________energy changes to __________ energy.

Pedaling is ________energy which causes the bike to move. The moving bike is also _________energy.

Here we see a young man, moving his legs to make the bike move.

If we were to trace this energy back further, we would see the man got his energy from his food. When food is digested ___________ energy is released. Following this path all the way back to photosynthesis, what was the source of this energy and almost all energy on Earth?

This light bulb contains a tiny wire called a filament.

When electricity flows through the filament, it gets hot and glows.

In this example, ______________energy changes to ___________ and __________ energy.

In this example, the electricity is provided by a battery. Do you remember what kind of energy is stored in a battery?

In this example, ______________energy changes to _________ energy and then to____________ and __________ energy.

In this example, natural gas is being burned to heat water . Do you remember what kind of energy is stored in natural gas?In this example, ______________energy changes to ___________ and __________ energy.

We put gasoline in our cars so that they can move. This gasoline is burned inside the engine. The engine also gets hot though this heat is not wanted .

In this example, __________ energy is changed to ___________ and _________ energy.

This finishes our lesson on energy. Is your personal energy strong enough to remember some of this exciting stuff?

Thanks to http://www.animationlibrary.com for their free animations.